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Subject[PATCH 33 of 38] xen: pack all irq-related info together
Date
From
Put all irq info into one struct.  Also, use a union to keep
event channel type-specific information, rather than overloading the
index field.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
---
drivers/xen/events.c | 184 ++++++++++++++++++++++++++++++++++++--------------
1 file changed, 135 insertions(+), 49 deletions(-)
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -51,18 +51,8 @@
/* IRQ <-> IPI mapping */
static DEFINE_PER_CPU(int, ipi_to_irq[XEN_NR_IPIS]) = {[0 ... XEN_NR_IPIS-1] = -1};

-/* Packed IRQ information: binding type, sub-type index, and event channel. */
-struct packed_irq
-{
- unsigned short evtchn;
- unsigned char index;
- unsigned char type;
-};
-
-static struct packed_irq irq_info[NR_IRQS];
-
-/* Binding types. */
-enum {
+/* Interrupt types. */
+enum xen_irq_type {
IRQT_UNBOUND,
IRQT_PIRQ,
IRQT_VIRQ,
@@ -70,14 +60,39 @@
IRQT_EVTCHN
};

-/* Convenient shorthand for packed representation of an unbound IRQ. */
-#define IRQ_UNBOUND mk_irq_info(IRQT_UNBOUND, 0, 0)
+/*
+ * Packed IRQ information:
+ * type - enum xen_irq_type
+ * event channel - irq->event channel mapping
+ * cpu - cpu this event channel is bound to
+ * index - type-specific information:
+ * PIRQ - vector, with MSB being "needs EIO"
+ * VIRQ - virq number
+ * IPI - IPI vector
+ * EVTCHN -
+ */
+struct irq_info
+{
+ enum xen_irq_type type; /* type */
+ unsigned short evtchn; /* event channel */
+ unsigned short cpu; /* cpu bound */
+
+ union {
+ unsigned short virq;
+ enum ipi_vector ipi;
+ struct {
+ unsigned short gsi;
+ unsigned short vector;
+ } pirq;
+ } u;
+};
+
+static struct irq_info irq_info[NR_IRQS];

static int evtchn_to_irq[NR_EVENT_CHANNELS] = {
[0 ... NR_EVENT_CHANNELS-1] = -1
};
static unsigned long cpu_evtchn_mask[NR_CPUS][NR_EVENT_CHANNELS/BITS_PER_LONG];
-static u8 cpu_evtchn[NR_EVENT_CHANNELS];

/* Reference counts for bindings to IRQs. */
static int irq_bindcount[NR_IRQS];
@@ -88,27 +103,107 @@
static struct irq_chip xen_dynamic_chip;

/* Constructor for packed IRQ information. */
-static inline struct packed_irq mk_irq_info(u32 type, u32 index, u32 evtchn)
+static struct irq_info mk_unbound_info(void)
{
- return (struct packed_irq) { evtchn, index, type };
+ return (struct irq_info) { .type = IRQT_UNBOUND };
+}
+
+static struct irq_info mk_evtchn_info(unsigned short evtchn)
+{
+ return (struct irq_info) { .type = IRQT_EVTCHN, .evtchn = evtchn };
+}
+
+static struct irq_info mk_ipi_info(unsigned short evtchn, enum ipi_vector ipi)
+{
+ return (struct irq_info) { .type = IRQT_IPI, .evtchn = evtchn,
+ .u.ipi = ipi };
+}
+
+static struct irq_info mk_virq_info(unsigned short evtchn, unsigned short virq)
+{
+ return (struct irq_info) { .type = IRQT_VIRQ, .evtchn = evtchn,
+ .u.virq = virq };
+}
+
+static struct irq_info mk_pirq_info(unsigned short evtchn,
+ unsigned short gsi, unsigned short vector)
+{
+ return (struct irq_info) { .type = IRQT_PIRQ, .evtchn = evtchn,
+ .u.pirq = { .gsi = gsi, .vector = vector } };
}

/*
* Accessors for packed IRQ information.
*/
-static inline unsigned int evtchn_from_irq(int irq)
+static struct irq_info *info_for_irq(unsigned irq)
{
- return irq_info[irq].evtchn;
+ return &irq_info[irq];
}

-static inline unsigned int index_from_irq(int irq)
+static unsigned int evtchn_from_irq(unsigned irq)
{
- return irq_info[irq].index;
+ return info_for_irq(irq)->evtchn;
}

-static inline unsigned int type_from_irq(int irq)
+static enum ipi_vector ipi_from_irq(unsigned irq)
{
- return irq_info[irq].type;
+ struct irq_info *info = info_for_irq(irq);
+
+ BUG_ON(info == NULL);
+ BUG_ON(info->type != IRQT_IPI);
+
+ return info->u.ipi;
+}
+
+static unsigned virq_from_irq(unsigned irq)
+{
+ struct irq_info *info = info_for_irq(irq);
+
+ BUG_ON(info == NULL);
+ BUG_ON(info->type != IRQT_VIRQ);
+
+ return info->u.virq;
+}
+
+static unsigned gsi_from_irq(unsigned irq)
+{
+ struct irq_info *info = info_for_irq(irq);
+
+ BUG_ON(info == NULL);
+ BUG_ON(info->type != IRQT_PIRQ);
+
+ return info->u.pirq.gsi;
+}
+
+static unsigned vector_from_irq(unsigned irq)
+{
+ struct irq_info *info = info_for_irq(irq);
+
+ BUG_ON(info == NULL);
+ BUG_ON(info->type != IRQT_PIRQ);
+
+ return info->u.pirq.vector;
+}
+
+static enum xen_irq_type type_from_irq(unsigned irq)
+{
+ return info_for_irq(irq)->type;
+}
+
+static unsigned cpu_from_irq(unsigned irq)
+{
+ return info_for_irq(irq)->cpu;
+}
+
+static unsigned int cpu_from_evtchn(unsigned int evtchn)
+{
+ int irq = evtchn_to_irq[evtchn];
+ unsigned ret = 0;
+
+ if (irq != -1)
+ ret = cpu_from_irq(irq);
+
+ return ret;
}

static inline unsigned long active_evtchns(unsigned int cpu,
@@ -129,10 +224,10 @@
irq_to_desc(irq)->affinity = cpumask_of_cpu(cpu);
#endif

- __clear_bit(chn, cpu_evtchn_mask[cpu_evtchn[chn]]);
+ __clear_bit(chn, cpu_evtchn_mask[cpu_from_irq(irq)]);
__set_bit(chn, cpu_evtchn_mask[cpu]);

- cpu_evtchn[chn] = cpu;
+ irq_info[irq].cpu = cpu;
}

static void init_evtchn_cpu_bindings(void)
@@ -146,15 +241,9 @@
desc->affinity = cpumask_of_cpu(0);
#endif

- memset(cpu_evtchn, 0, sizeof(cpu_evtchn));
memset(cpu_evtchn_mask[0], ~0, sizeof(cpu_evtchn_mask[0]));
}

-static inline unsigned int cpu_from_evtchn(unsigned int evtchn)
-{
- return cpu_evtchn[evtchn];
-}
-
static inline void clear_evtchn(int port)
{
struct shared_info *s = HYPERVISOR_shared_info;
@@ -239,6 +328,8 @@
if (irq == nr_irqs)
panic("No available IRQ to bind to: increase nr_irqs!\n");

+ dynamic_irq_init(irq);
+
return irq;
}

@@ -253,12 +344,11 @@
if (irq == -1) {
irq = find_unbound_irq();

- dynamic_irq_init(irq);
set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
handle_level_irq, "event");

evtchn_to_irq[evtchn] = irq;
- irq_info[irq] = mk_irq_info(IRQT_EVTCHN, 0, evtchn);
+ irq_info[irq] = mk_evtchn_info(evtchn);
}

irq_bindcount[irq]++;
@@ -282,7 +372,6 @@
if (irq < 0)
goto out;

- dynamic_irq_init(irq);
set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
handle_level_irq, "ipi");

@@ -293,7 +382,7 @@
evtchn = bind_ipi.port;

evtchn_to_irq[evtchn] = irq;
- irq_info[irq] = mk_irq_info(IRQT_IPI, ipi, evtchn);
+ irq_info[irq] = mk_ipi_info(evtchn, ipi);

per_cpu(ipi_to_irq, cpu)[ipi] = irq;

@@ -327,12 +416,11 @@

irq = find_unbound_irq();

- dynamic_irq_init(irq);
set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
handle_level_irq, "virq");

evtchn_to_irq[evtchn] = irq;
- irq_info[irq] = mk_irq_info(IRQT_VIRQ, virq, evtchn);
+ irq_info[irq] = mk_virq_info(evtchn, virq);

per_cpu(virq_to_irq, cpu)[virq] = irq;

@@ -361,11 +449,11 @@
switch (type_from_irq(irq)) {
case IRQT_VIRQ:
per_cpu(virq_to_irq, cpu_from_evtchn(evtchn))
- [index_from_irq(irq)] = -1;
+ [virq_from_irq(irq)] = -1;
break;
case IRQT_IPI:
per_cpu(ipi_to_irq, cpu_from_evtchn(evtchn))
- [index_from_irq(irq)] = -1;
+ [ipi_from_irq(irq)] = -1;
break;
default:
break;
@@ -375,7 +463,7 @@
bind_evtchn_to_cpu(evtchn, 0);

evtchn_to_irq[evtchn] = -1;
- irq_info[irq] = IRQ_UNBOUND;
+ irq_info[irq] = mk_unbound_info();

dynamic_irq_cleanup(irq);
}
@@ -493,8 +581,8 @@
for(i = 0; i < NR_EVENT_CHANNELS; i++) {
if (sync_test_bit(i, sh->evtchn_pending)) {
printk(" %d: event %d -> irq %d\n",
- cpu_evtchn[i], i,
- evtchn_to_irq[i]);
+ cpu_from_evtchn(i), i,
+ evtchn_to_irq[i]);
}
}

@@ -592,7 +680,7 @@
BUG_ON(irq_bindcount[irq] == 0);

evtchn_to_irq[evtchn] = irq;
- irq_info[irq] = mk_irq_info(IRQT_EVTCHN, 0, evtchn);
+ irq_info[irq] = mk_evtchn_info(evtchn);

spin_unlock(&irq_mapping_update_lock);

@@ -702,8 +790,7 @@
if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
continue;

- BUG_ON(irq_info[irq].type != IRQT_VIRQ);
- BUG_ON(irq_info[irq].index != virq);
+ BUG_ON(virq_from_irq(irq) != virq);

/* Get a new binding from Xen. */
bind_virq.virq = virq;
@@ -715,7 +802,7 @@

/* Record the new mapping. */
evtchn_to_irq[evtchn] = irq;
- irq_info[irq] = mk_irq_info(IRQT_VIRQ, virq, evtchn);
+ irq_info[irq] = mk_virq_info(evtchn, virq);
bind_evtchn_to_cpu(evtchn, cpu);

/* Ready for use. */
@@ -732,8 +819,7 @@
if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
continue;

- BUG_ON(irq_info[irq].type != IRQT_IPI);
- BUG_ON(irq_info[irq].index != ipi);
+ BUG_ON(ipi_from_irq(irq) != ipi);

/* Get a new binding from Xen. */
bind_ipi.vcpu = cpu;
@@ -744,7 +830,7 @@

/* Record the new mapping. */
evtchn_to_irq[evtchn] = irq;
- irq_info[irq] = mk_irq_info(IRQT_IPI, ipi, evtchn);
+ irq_info[irq] = mk_ipi_info(evtchn, ipi);
bind_evtchn_to_cpu(evtchn, cpu);

/* Ready for use. */



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